It is known that the systems that use pumps activated from a motor of continuous current have the need to generate a minimum power for their operation. In particular, the larger the system hydraulics pressure, the larger the need of energy for the motor to reach a minimum rotation. In a normal application, the energy fluctuations, in function of the natural variables of solar radiation or wind speed, they make the system suffers continuous paralyzations (periods of low level of solar radiation or of wind). To eliminate or to reduce such effects, they usually employ great quantities of solar cells or larger aeolic power generation, which increases the systems implantation cost. Another solution to overcome the above drawbacks is the use of banks of supplemental batteries that store energy during periods of low energy and transfer to the pump in order to provide enough energy for activation. However, the cost involved with this solution makes it completely unfeasible.
Actuation systems of electromechanical pumps are also known. They process the electrical power only supplied by the solar cells, and convert the energy in variables pulses and spaced regarding the level of solar radiation. These systems operate in analogous form, where the circuit signals are treated in direct form, not allowing attending to the variables to which the system is subject, without alterations in the electronic project; this carries circuit costs increase, it limits the system input power, does not allow the use of higher performance pumps and does not allow its use in aeolic generators, due to the high power supplied by these devices. The use of such techniques reduces the system revenue, increasing the installed power cost of solar cells by pumped liter. Further, the protection means for the circuit are onerous and inefficient, operating only with independent systems. An example of such a system is described in Brazilian patent PI 8204205, deposited on Jul. 16, 1982.